Off the east coast of Abaco lies one of the longest barrier reefs in the world. Some authorities suggest it is the third longest, but the exact ranking of the top dozen coral barriers is a matter for considerable debate. None of the lists I have just checked agree, except that the Great Barrier Reef is the outright winner. I suspect that the problem lies in the loosely generalised description of ‘barrier reef’ and in variations of the appropriate criteria for determining length (it may also depend on who is doing the measuring, of course).
Melinda Rogers of Dive Abaco took this bright sunlit ‘Coralscape’ in the Fowl Cays National Park. It’s a place I have tentatively snorkelled around with great pleasure, despite being in the top dozen most useless swimmers in the world (my appalling underwater videos were disqualified from the rankings for being… rank).
Nearly 4 weeks after the devastation of Hurricane Dorian, the island and its cays are beginning to emerge gradually from the wreckage and the desolation. The extent of the disaster on the ground is clear, not least from the aerial photos – first drone, then plane, and now Google – of ‘before’ and ‘after’.
At the stage, it isn’t possible to determine the extent to which the underwater world has been affected. The storm surge was huge and the waves were savage. The progress of the storm was slow (and it went on to stall over equally damaged Grand Bahama). Who knows the effect on the corals and other reef life for which Abaco is renowned.
This pictorial post is a reminder of how things were below the surface of Abaco waters before Dorian struck. If it lifts spirits to any degree, I shall be glad.
All these photos are by Melinda Rodgers who, with Capt Keith, are DIVE ABACO. Many will know how badly they have fared, being in the heart of Marsh Harbour. We wish them a speedy return to the wonderful enterprise they have run for many years. I’m pleased to be able to show the beauty of the reefs in happier times from their archive.
FLAMINGO TONGUE SNAILS Cyphoma gibbous are small marine gastropod molluscs related to cowries. The living animal is brightly coloured and strikingly patterned, but that colour only exists in the ‘live’ parts – the so-called ‘mantle’. The shell itself is usually pale, and characterised by a thick ridge round the middle. These snails live in the tropical waters of the Caribbean and the wider western Atlantic. Whether alive or dead, they are gratifyingly easy to identify.
THE IMPORTANCE OF CORAL
Flamingo tongue snails feed by browsing on soft corals. Often, they will leave tracks behind them on the coral stems as they forage (see image below). But corals are not only food – they provide the ideal sites for the creature’s breeding cycle.
Adult females attach eggs to coral which they have recently fed upon. About 10 days later, the larvae hatch. They eventually settle onto other gorgonian corals such as Sea Fans. Juveniles tend to live on the underside of coral branches, while adults are far more visible and mobile. Where the snail leaves a feeding scar, the corals can regrow the polyps, and therefore the snail’s feeding preference is generally not harmful to the coral.
The principal purpose of the patterned mantle of tissue over the shell is to act as the creature’s breathing apparatus. The tissue absorbs oxygen and releases carbon dioxide. As it has been (unkindly?) described, the mantle is “basically their lungs, stretched out over their rather boring-looking shell”.
THREATS AND DEFENCE
The species, once common, is becoming rarer. The natural predators include hogfish, pufferfish and spiny lobsters, though the spotted mantle provides some defence by being rather unpalatable. Gorgonian corals contain natural toxins, and instead of secreting these after feeding, the snail stores them. This supplements the defence provided by its APOSEMATIC COLORATION, the vivid colour and /or pattern warning sign to predators found in many animal species.
It comes as little surprise to learn that man is now considered to be the greatest menace to these little creatures, and the reason for their significant decline in numbers. The threat comes from snorkelers and divers who mistakenly / ignorantly think that the colour of the mantle is the actual shell of the animal, collect up a whole bunch from the reef, and in due course are left with… dead snails and “boring-looking shells” (see photos below). Don’t be a collector; be a protector…
The photos below are of nude flamingo tongue shells from the Delphi Club Collection. Until I read the ‘boring-looking shell’ comment, I believed everyone thought they were rather lovely… I did, anyway. You decide!
Image Credits: Melinda Rogers / Dive Abaco; Keith Salvesen / Rolling Harbour
Four years ago a young English friend of ours, Oscar Ward, was lucky enough to be offered an internship with the Bahamas Marine Mammal Research Organisation (BMMRO). At the time, he was post-school, and waiting to start a degree course in marine biology at university. He had no practical experience at all, so he had to progress from the menial tasks (scraping barnacles off the bottom of the research boat) to the more adventurous (whale poop-scooping) to the scholarly (collection and analysis of samples and data, including audio file matching of whale calls for identification). The need for hard work, concentration and accuracy were made clear from the outset… and as you will see, Oscar’s short internship has stood him in very good stead during his university course.
Oscar weekending at Gilpin Point – self-sufficient
From a promising start on Abaco, and with 2 year’s study behind him, Oscar is currently spending the 3rd year of his 4-year course in Australia, working with The Australian Institute of Marine Science. He has been involved in a number of complex projects focussed on corals and reef life – as we all know, a matter of huge concern – and the projections for the future of the reef systems in a time of warming seas and raised acid levels. Oscar also assists PhD students, for example examining the damaging effects of parasitic worms on coral; and the effect of changing light conditions on corals.
Much of Oscar’s time has been spent doing fieldwork. Often he is at sea, monitoring and collecting samples in the Southern Great Barrier Reef, diving two or three times a day. This work is often carried out in restricted or preservation zones, and with ever-present manta rays, sharks and sea turtles around him.
Right now Oscar is involved with the investigations into the recent bleaching events, work that is at the forefront of serious concern for the GBR and far beyond. I have recently corresponded with him – he has definitely not forgotten that his grounding for the fieldwork and studies that he is engaged in – and very likely his career – came from his time on Abaco and the lessons he learned during his time with the BMMRO at Sandy Point. (In part 2: another good intern, currently at Sandy Point)
All photos: Oscar Ward (the header image is taken from a research vessel – no idea how, maybe a drone with fish-eye lens?)
This post needs no commentary from me, nor my larky intrusions. These wonderful images from Melinda Riger speak for themselves. You’ll see a wide variety of soft and hard corals in the images below (prize** for the full list). If these superb photos don’t want to make you want to grab a snorkel, mask and flippers, then… well, that would be a very great shame.
**the prize is the usual legendary bottle of Kalik. Or do I mean mythical?
All wonderful photos by Melinda Riger, Grand Bahama Scuba. All corals also available in a wide range of colours in Abaco waters. See them there on the third largest barrier reef in the world (and in rather better nick that the greatest, by all accounts).
The little blue chromis Chromis cyanea will be instantly familiar to any snorkeler or scuba diver on the coral reefs of the Bahamas. These ever-present small fish – 6 inches long at most – are remarkable for their iridescent deep blue colour that flashes as they dart in and out of the coral and anemones of the reef.
Although at first sight this chromis species – one of many – looks blue all over, adults have a black dorsal stripe and black edging to their fins. They make colourful additions to aquariums, though to my mind they look far more attractive nosing about the reefs foraging for the zooplankton upon which they feed (see header image for details…)
The blue chromis was the second fish species I encountered on my first ever reef dive, at Fowl Cay Marine Preserve with Kay Politano. The first fish was the endearingly inquisitive sergeant major with its smart black and yellow stripes which came right up to my googles to eyeball me. I loved that, even though my pitiful swimming technique meant that I had plenty of other distractions, not least remembering to breathe. Air, that is, rather than water.
SO JUST HOW BIG ARE THESE FISH, COMPARED, SAY, TO A BLUE TANG?
Blue Tang with blue chromis in its wake
All photos Melinda Riger of Grand Bahama Scube, except the penultimate by James St John, taken in San Salvador
The reefs of the northern Bahamas, as elsewhere in the world, are affected by two significant factors: climate change and pollution. Stepping carefully over the sharp pointy rocks of controversy, I’ve avoided the term ‘global warming’ and any associated implication that humans (oh, and methane from cows) are largely to blame for the first factor; but on any view, ocean pollution is the responsibility of mankind (and not even the cows).
That said, an exploration of the reefs of Abaco or Grand Bahama will reveal not just the astounding variety of mobile marine life but also the plentiful and colourful static marine life – for example the beautiful and Christmassy orange cup coral in the header image. Here are some more corals from the reefs, with a mix of sponges added in.
This rather intriguing photo shows a hermit crab’s conch home that presumably the occupant grew out of and left behind in the delicate coral branches as it went search of a more spacious shell dwelling.
Credits: All these wonderful photos are by Melinda Riger of Grand Bahama Scuba; tendentious reef health observations are mine own…
I wrote about FLAMINGO TONGUE SNAILS Cyphoma gibbous more than two years ago. They have not changed noticeably since then but this site has – in scope, available material and audience. So I am revisiting these small marine gastropod molluscs, which are related to cowries. The live animal is brightly coloured and strikingly patterned, but that colour only exists in the ‘live’ parts – the ‘mantle’. The shell itself is usually pale and characterised by a thick ridge round the middle. These snails live in the tropical waters of the Caribbean and the wider western Atlantic. Whether alive or dead, they are gratifyingly easy to identify.
FLAMINGO TONGUE SNAIL ON A PURPLE ROPE SPONGE
FEEDING ON A CORAL STEM
This snail is snacking on a coral stem, leaving a feeding track behind it. The structural shell ridge is clearly visible beneath the distinctively marked live tissue of these creatures.
The flamingo tongue feeds by browsing on soft corals. Adult females attach eggs to coral which they have recently fed upon. About 10 days later, the larvae hatch. They eventually settle onto other gorgonian corals such as Sea Fans. Juveniles tend to live on the underside of coral branches, while adults are far more visible and mobile. Where the snail leaves a feeding scar, the corals can regrow the polyps, and therefore the snail’s feeding preference is generally not harmful to the coral.
The principal purpose of the mantle of tissue over the shell is as the creature’s breathing apparatus. The tissue absorbs oxygen and releases carbon dioxide. As I have seen it described (unkindly?) “it’s basically their lungs, stretched out over their rather boring-looking shell”.
This snail species, once common, is becoming rarer. The natural predators include Hogfish, Pufferfish and Spiny Lobsters, though the spotted mantle provides some defence by being rather unpalatable. Gorgonian corals contain natural toxins and instead of secreting these, the snail stores them. This supplements the defence provided by its APOSEMATIC COLORATION, the vivid colour and /or pattern warning sign to predators found in many species.
It comes as little surprise to learn that man is now considered to be the greatest menace to these little creatures, and the reason for their significant decline in numbers. The threat comes from snorkelers and divers who mistakenly / ignorantly think that the colour of the mantle is the shell of the animal, collect up a whole bunch from the reef, and in due course are left with… “boring-looking shells” (see photos below). Don’t be a collector; be a protector…
These photos are of flamingo tongue shells from the Delphi Club Collection. Until I read the ‘boring-looking shell’ comment, I believed everyone thought they were rather lovely… I did, anyway. You decide!
Finally, a couple of videos. The first is rather charmingly titled ‘FLAMINGO TONGUES DOING…. SOMETHING’. Any (printable but amusing) suggestions via the Comment box are welcome. The second punchily summarises this post in 30 seconds. Maybe that’s all that was needed!
RED REEF RESIDENTS: A RUFOUS ROUND-UP IN THE BAHAMAS
It’s sunny and very hot. Time to take another dive with Melinda to see what is going on under water around the reefs. Here are some residents, a somewhat loose description since some of the denizens featured are not especially active. But they are alive, so they qualify by my wide rules. And please may we not get into a discussion about where precisely red and orange overlap. It’s a grey area. And it’s too hot to argue about it… Let’s start with three types of GROUPER that may be spotted in the northern Bahamas. In fact, they are always spotted. One of my favourite pictures is the Graysby – it’s such a great expression, and he really rocks the spots!
QUEEN ANGELFISH: COLOURFUL CORAL ROYALTY – BAHAMAS REEF FISH (13)
One of the earliest posts in the Bahamas Reef Fish series was about Queen Angelfish Holacanthus ciliaris, and you can see it HERE. I make no apology for returning with some more recent photos from Melinda Riger – these fish deserve plenty of attention for their wonderful bright presence that stands out even amongst the colourful corals of the reef.
This first image is remarkable for its clarity and composition. What, I wonder, is the fish saying to Melinda as she presses the camera button? All caption suggestions welcome…
Angelfish are quite happy to swim round either way up
The juvenile of the species, nosing around the coral for tasty morsels, is equally colourful
We are back in the realm of ‘animal, vegetable or mineral?’. Dive down a few feet – inches, even – to the reef, and… is this thing waving about here a plant or a creature? And is that colourful lump over there a bit of inanimate rock or a living thing?
1. FEATHER DUSTERS
Not in fact pretty frilly-fringed plants, but worms among the coral. The tiny electric blue fish are Blue Chromis, ubiquitous around the reefs.
Here the feather dusters have attached themselves to a sea fan, a ‘gorgonian’ coral
Moored on part of an old wreck
A different form of duster with remarkable feathered tentacles
2. BASKET STARS Creatures in the same family group as brittle stars. Take a close look at the remarkable transformation in the two photographs. The top image is taken in daylight. The star is off duty and enjoying some downtime. However the second image is the same view at night, with the star fully open and waiting to harvest whatever micro-morsels come its way. The star has truly ‘come out at night’.
3. CORKY SEA FINGER Another form of gorgonian coral, sometimes known as dead man’s fingers… **
4. GOLDEN ZOANTHIDS Coral forms living on a Green Rope Sponge. Some zoanthids contain a deadly poisin called palytoxin, which may do unspeakable things to your heart. Like stop it. Luckily, none so unpleasant live in the Bahamas (or so the Bahamian Tourist Board would no doubt wish me to make clear).
I realise that calling this occasional series ‘Reef Gardens’ is a bit of a misnomer. They are in fact Reef Zoos. The previous posts are as follows:
Image credits, with thanks: Melinda Riger @ Grand Bahama Scuba
** I knew this image reminded me of something… or someone. And (superannuated British rockers out there), is it not exactly like the hairdo of one of the guys in Mott the Hoople, a band lifted from relative obscurity to fame by being gifted a song by David Bowie? Guitarist. Ian Hunter. Take a look at him now… and just imagine then
UNDERWATER REEF GARDENS IN THE BAHAMAS (2): CORALS
This is part 2 of a series that started out HEREwith a selection of anemones, basket stars and Christmas tree worms. The images below show a wide variety of corals. In among them are also sponges and anemones. These photos are evidence of a healthy reef environment in the waters of the northern Bahamas. Abaco’s coral reef is the third largest barrier reef in the world (yes, I hear you – the Great Barrier… And the second is???), providing wonderful and accessible diving / snorkelling opportunities. However, monitoring shows that the incidence of coral bleaching and disease is increasing in the Bahamas, as elsewhere in the world. It’s a sobering thought that your grandchildren may never swim in an environment with any of the living corals shown below…
Albert King, Lead Belly and Mike Bloomfield are prime examples of foremost bluesmen guitar-slingers who, in their own distinctive styles, favoured the key of… I’m sorry, what did you say? Oh yes, quite right. My misunderstanding. Apologies, I’ll take it from the top…
Deep blue sea. Deep blue fish. *Deep breath*. All better now. The fish below may all readily be found nosing around the coral reefs of the Bahamas in a leisurely manner. Mostly, they are feeding. Fowl Cay Marine Preserve, Abaco, is a great place for watching them. No need to have all the gear – a simple snorkel, mask and flippers, and an ability to float a bit, would be sufficient.
BLUE CHROMIS Chromis cyanea
These dazzling little blue fish will be one of the first you’ll meet (along with the omnipresent yellow and black striped sergeant majors, so friendly they will come right up to your mask). You can’t miss them. Though very small, their electric blue colouring cuts through the water even on the dullest of days up-top. They can reach 5 inches in length, but most that you see will be tiddlers. They are frequently seen in the company of larger fish.
BLUE PARROTFISH Scarus coeruleus
Parrotfish play a vital part in the ecology and health of the coral reef. They graze on algae, cleaning the coral and grinding the surface with their teeth. They take the nutrients and excrete the rest as… sand. This helps to form your beach! To find out more about their uses and habits, click PARROTFISH. You’ll find a great deal of interesting info about the species, conveniently compressed into factual bullet points.
BLUE TANG Acanthurus coeruleus
The blue tang is a type of surgeonfish, all-blue except for a yellow spot near the tail. The blueness can vary considerably, from very pale to dark. They tend to swim elegantly around in large groups.
Here are some images of schools of blue tang that I took with a cheapo underwater camera at Fowl Cay. They are a lovely sight as they drift slowly past alongside the reef. The top one also has a sergeant major (see above).
CREOLE WRASSE Clepticus parrae
This wrasse can grow up to a foot long, and may be found at considerable depths on deep-water reefs – 300 feet or more. They are active by day, and hide in rock clefts at night. This species is sociable, moving around in shoals. They develop yellow markings with age.
QUEEN TRIGGERFISH Balistes vetula
There are several species of triggerfish. The queen is capable of changing colour to match its surroundings, or (it is said) if subjected to stress. I think we have all been there. It is an aggressive and territorial fish, and its favourite prey is the sea urchin, a testament to its courage…
QUEEN ANGELFISH (JUVENILE)
I have featured this species before HERE, and strictly it as much yellow as blue. But the blue earns double points, surely, for its startling vividness. Anyway, I like the way it hangs casually upside down, and the bubbles in this photo.
Credits: Good photos – Melinda Riger of Grand Bahama Scuba; Poor photos – RH
From time to time I end a post with something musical. Just for fun (toxic concept). So here is a real “Slow Blues in C” from the fantastic guitarist Stefan Grossman off his eclectic ‘Yazoo Basin Boogie’ album. 22 quality tracks. Buy from Am*z*n – much cheaper than iT*nes.
I usually have 3 or 4 planned posts on the go. Some are quick to compose, some are not. Especially those requiring technical input from the technically unsound – downloading a video, changing the file format, editing and polishing, uploading to a compatible ‘carrier’ etc. I’ve been meaning to get round to making some fish and reef videos from footage of a trip with Kay Politano of Abaco Above & Below. Now I have…
If you are tolerant enough to at least start this one, which focusses on coral, can I restate the excuses? I swim like a panicking cat. I hadn’t snorkelled for a great many decades years until 2011. I was a stranger to underwater scenery, let alone photography. I wave my tiny camera around too excitedly, though not deliberately to inflict seasickness on hapless viewers… It is a bit less bad this time round, however. Luckily I can tell from my stats if anyone has bothered to click on the video below, and you can rely on me to trash the thing if I find a paltry (or non-existent) response. Best just to watch on the small screen, though.
With those dire warnings, here is the video. I would be very interested to ID all the corals that can be seen. There are the easy ones like sea fan, elkhorn, mustard hill, brain… but what’s that one over there? No, behind the waving one…? Comments / suggestions welcome. And if you don’t much care for coral, there are some pretty fish to look at…
Music Credit: Adrian Legg’s ‘Old Friends’, from ‘Guitar Bones’
ADDENDUM JAN 13 I am really grateful to Capt Rick Guest for taking the time to view the video, and the trouble to analyse the contents. He has very helpfully highlighted many points of interest in the film, both as to coral and as to fish, so I’ll post his commentary in full, with my thanks. Of both interest and concern are Rick’s remarks about the Elkhorn Coral. I had wondered about its bleached look. It’s dying…
At 0:36 a lavender Sea Fan…(Gorgonia ventalina).
At 0:52 Yellow “Leaf”,or “Letuce Coral”. Agaricia species growing around a living soft coral called a “Sea Rod”. Soft Corals have living polyps which feed on plankton just like the hard corals.
At 1:02 More Agaricia, and a small Brain Coral at bottom. Either a Diploria, or Colpophylia species.
At 1:10 A Sergent Major fish, (Abedefduf saxatilus). One of my favorite Taxanomic names! Behind is mostly dead, Elkhorn Coral. The white areas being indicative of “White Plague”. A disease responsible for Coral Whiting…..Death!
At 1:37 A Blue Tang swims over some “Mustard Coral”… Porites porites.
At 1:55 A chubby “Chub” swims by. Likes caves and caverns and edible, but not palatable.
At 2:33-38 Much coral bleaching damage here on these Elkhorn Corals.
At 2:40-48 A Thalassoma bifaciatum,or “Blue Headed Wrasse” is swimmin’ about. This guy used to be a lady,but he’s a product of Protandric Hermaphrodism! When there’s a paucity of males in the area, a yellow female will step up and become a male for the school.
At 3:29 Lower right: a fine example of Millepora complanata,”Fire Coral”. Fire Coral is more related to Man-O-War, and jellyfish than Corals.
Caribbean coral reefs are in danger of disappearing, depriving the world of one of its most beautiful and productive ecosystems
Guardian: Monday 10 September 2012 03.00 BST
• INTERACTIVE GUIDE: CORAL REEFS AROUND THE WORLD
• WHAT DOES A CORAL REEF SOUND LIKE?
A pair of French angelfish enjoy the coral reef in the Caribbean Sea. Photograph: Marcus Mays for the Guardian
Caribbeancoralreefs – which make up one of the world’s most colourful, vivid and productive ecosystems – are on the verge of collapse, with less than 10% of the reef area showing live coral cover.
With so little growth left, the reefs are in danger of utter devastation unless urgent action is taken, conservationists warned. They said the drastic loss was the result of severe environmental problems, including over exploitation,pollutionfrom agricultural run-off and other sources, andclimate change.
The decline of the reefs has been rapid: in the 1970s, more than 50% showed live coral cover, compared with 8% in the newly completed survey. The scientists who carried it out warned there was no sign of the rate of coral death slowing.
Coral reefs are a particularly valuable part of the marine ecosystem because they act as nurseries for younger fish, providing food sources and protection from predators until the fish have grown large enough to fend better for themselves. They are also a source of revenue from tourism and leisure.
Carl Gustaf Lundin, director of the global marine and polar programme at the International Union for Conservation of Nature (IUCN), which published the research, said: “The major causes of coral decline are well known and include overfishing, pollution, disease and bleaching caused by rising temperatures resulting from the burning of fossil fuels. Looking forward, there is an urgent need to immediately and drastically reduce all human impacts [in the area] if coral reefs and the vitally important fisheries that depend on them are to survive in the decades to come.”
Warnings over the poor state of the world’s coral reefs have become more frequent in the past decades as pollution, increasing pressure on fish stocks, and the effects of global warming on the marine environment – in the form of higher sea temperatures and slightly elevated levels of acidity in the ocean – have taken their toll.
This decline is likely to have severe impacts on coastal villages, particularly in developing countries, where many people depend on the reefs for fishing and tourism. Globally, about 275 million people live within 19 miles of a reef.
IUCN, which is holding its quadrennial World Conservation Congress on Jeju island in South Korea this week, said swift action was vital. The organisation called for catch quotas to limit fishing, more marine-protected areas where fishing would be banned, and measures that would halt the run-off of fertilisers from farmland around the coast. To save reefs around the world, moves to stave off global warming would also be needed, the group said.
On a few of the more remote Caribbean reefs, the situation is less dire. In the Netherlands Antilles, Cayman Islands and a few other places, the die-off has been slower, with up to 30% coverage of live coral still remaining. The scientists noted that these reefs were in areas less exposed to human impact from fishing and pollution, as well as to natural disasters such as hurricanes.
Kasia’s back! She recently explored a rather unpromising-looking stretch of Abaco coastline, and it proved to be anything but… Kasia writes: The story goes: one day I took myself for a walk and a bit of beachcombing. I usually don’t bring my camera with me but luckily this time I did. This particular beach looks very barren but on close inspection and a patient eye there are some lovely treasures to be found. Here are some of the treasures I captured!
A tangle of 3 bleached trees, with their roots apparently intertwined
Great close-ups… are those eggs behind this first one? There’s a similar image in theMacmillan ‘Marine Life of the Caribbean’but unfortunately neither the caption nor the text refers to them. ADDENDUM: Colin Redfern writes: The “eggs” behind the chiton are fecal pellets
WEST INDIAN TOP-SHELLS(Cittarium Pica)
In this image, several very small chitons can also be seen on the rock
It looks as if someone… or something… has been having a Nerite feast on the shore. A bird maybe? I had taken the shells above and below to be another variety of Nerite, but as so often scientist and shell expert Colin Redfern has kindly corrected the error. He writes:“Very nice photos. The “nerite feast” is actually a pile of broken West Indian Top-shells (Cittarium pica). The photo immediately above shows a live group of the same species. This is what Bahamians call a whelk (or wilk), and in the lower photo they have been harvested, probably for a stew.
ROCK POOL MISCELLANY
I am trying to ID a much as I can in this pool. All suggestions welcome via ‘Leave a Comment’. So far, the corals are Brain Coral and Pink Coral (I think) but I am going see what else can be given a name…
These are my favourite! 🙂 Kasia
COMET SEA STAR (possibly juvenile, with 3 such short stubs?)
A SPONGE (?) OF SOME SORT (any help with ID appreciated…)
These two different types of coral skeleton are from the northern end (and just beyond) of the Delphi beach. The red marking on the second coral is some kind of natural accretion, I think – I have temporarily lost the exact details somewhere on my hard drive, but doubtless they will turn up sooner or later… You will find these red patches on shells as well as coral
COMMON ROSE CORAL
ANY IDEAS – OR IS THIS WORM-RELATED?
Another dramatic coral you may come across – not least because there are usually one or two in the beach-harvested collection on the steps down to the beach – is Brain Coral (Diploria). Here is an example (Photo credit J. Stuby)
Nerites are small sea-snails (gastropod molluscs) found in tropical waters around the world. Precise ID of the many types is confused by the different names used for many of them, both taxonomic and local. The majority of the black and white nerites in the pile below, all collected from the Delphi beach, are Checkered Nerites (Nerita Tessellata). In the heap there are a few larger whiter shells with red markings, which are the Four-Toothed Nerite (Nerita Versicolor).
Here are some of the above shells showing their varying patterns and sizes, seen with a few grains of sand for comparison. The 3 larger whiter ones with the flecks of red on them are the Four-Toothed Nerites.
Here are 3 example shells in close-up, together with a tiny, perfect Dwarf Atlantic Planaxis (Hinea lineata) at the end (previously misidentified as a Littorine). I didn’t notice it until I was sorting through the shells – in fact you can just see it towards the bottom right of the previous photo, above the small nerite that’s on its back. It may even have fallen out of a nerite, as did many of the sand grains.
These four upturned nerites show the dentate entrance, common (to a greater or lesser extent) to most nerites – maybe all. The top row are Four-toothed Nerites; the bottom row are Checkered Nerites. Another Nerite type found in the Bahamas is the Bleeding-tooth nerite (Nerita Peloronta). These are similar to the top ones, but have vivid orangey-red markings on the ‘teeth’ – hence their name.
Nerites, sand grains and the Planaxis: size comparison
A close up of the Planaxis, showing how amazingly detailed the pattern of such a tiny shell can be
All this may sound a bit learned and somewhat solemn. Dull even. In fact I had absolutely no idea about any of the above details until I got these shells out of their glass jar last week to photograph (apologies for using a chopping board) and did some digging… So if any shellologists or neritophiles read this and have corrections to suggest, be my guest… Use the comment box or the email address on theCONTACTpage. ADDENDUM: many thanks to Colin Redfern for confirming the small nerites as Checkered, as opposed to Zebra; and the ‘littorine’ as a Dwarf Atlantic Planaxis Hinea lineata